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Related papers: Dynamics of Molecular Clouds

200 papers

We study the formation of giant dense cloud complexes and of stars within them by means of SPH numerical simulations of the mildly supersonic collision of gas streams (``inflows'') in the warm neutral medium (WNM). The resulting…

By performing $N$-body simulations, we investigated fundamental processes of collisions between dust aggregates composed of submicron-sized icy dust monomers. We examined the mass distribution of fragments in the collisional outcomes in a…

Earth and Planetary Astrophysics · Physics 2023-02-22 Yukihiko Hasegawa , Takeru K. Suzuki , Hidekazu Tanaka , Hiroshi Kobayashi , Koji Wada

The recent paper by Heyer et al (2009) indicates that observations of size, linewidth and column density of interstellar clouds do not agree with simple virial equilibrium (VE) as a balance between gravitational and kinetic energies in the…

Astrophysics of Galaxies · Physics 2015-05-28 George Field , Eric Blackman , Eric Keto

Turbulent fragmentation determines where and when protostellar cores form, and how they contract and grow in mass from the surrounding cloud material. This process is investigated, using numerical models of self-gravitating molecular cloud…

Astrophysics · Physics 2010-04-06 Ralf Klessen

We investigate the fragmentation process of solid materials with crystalline and amorphous phases using the discrete element method. Damage initiates inside spherical samples above the contact zone in a region where the circumferential…

Recent observations suggest galaxies may ubiquitously host a molecular component to their multiphase circumgalactic medium (CGM). However, the structure and kinematics of the molecular CGM remains understudied theoretically and largely…

Astrophysics of Galaxies · Physics 2023-08-16 Ryan Jeffrey Farber , Max Gronke

The evolution of self-gravitating clouds of isothermal gas forms the basis of many star formation theories. Therefore it is important to know under what conditions such a cloud will undergo homologous collapse into a single, massive object,…

Astrophysics of Galaxies · Physics 2018-08-08 David Guszejnov , Philip F. Hopkins , Michael Y. Grudic , Mark R. Krumholz , Christoph Federrath

The results of study of the gravitational fragmentation in the interstellar medium (ISM) by clump-clump collisions are presented. We suggest, that collision of clumps, that are subparts of Giant Molecular Clouds (GMC) may be on of the basic…

Astrophysics · Physics 2012-07-04 S. B. Vinogradov , P. Berczik

It has been shown that fragmentation within self-gravitating, turbulent molecular clouds ("turbulent fragmentation") can naturally explain the observed properties of protostellar cores, including the core mass function (CMF). Here, we…

Astrophysics of Galaxies · Physics 2018-04-25 David Guszejnov , Philip F. Hopkins

A cloud of gas collapsing under gravity will fragment. We present a new theory for this process, in which layers shocked gas fragment due to their gravitational instability. Our model explains why angular momentum does not inhibit the…

Astrophysics · Physics 2011-04-28 M. Wilkinson , B. Mehlig , M. A. Morgan

Molecular clouds (MCs) are stellar nurseries, however, formation of stars within MCs depends on the ambient physical conditions. MCs, over a free-fall time are exposed to numerous dynamical phenomena, of which, the interaction with a thin,…

Astrophysics of Galaxies · Physics 2015-05-20 S. Anathpindika , H. C. Bhatt

The morphology and kinematics of molecular clouds (MCs) are best explained as the consequence of super--sonic turbulence. Super--sonic turbulence fragments MCs into dense sheets, filaments and cores and large low density ``voids'', via the…

Astrophysics · Physics 2008-11-26 Paolo Padoan , AAke Nordlund

The collapse and fragmentation of initially prolate and oblate, magnetic molecular clouds is calculated in three dimensions with a gravitational, radiative hydrodynamics code. The code includes magnetic field effects in an approximate…

Astrophysics of Galaxies · Physics 2010-01-15 Alan P. Boss

We develop an analytic framework to understand fragmentation in turbulent, self-gravitating media. Previously, we showed some properties of turbulence can be predicted with the excursion-set formalism. Here, we generalize to fully…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-02 Philip F. Hopkins

We examine the formation of molecular gas behind shocks in atomic gas using a chemical/dynamical model, particular emphasis is given to constraints the chemistry places on the dynamical evolution. The most important result of this study is…

Recent models of molecular cloud formation and evolution suggest that such clouds are dynamic and generally exhibit gravitational collapse. We present a simple analytic model of global collapse onto a filament and compare this with our…

Astrophysics of Galaxies · Physics 2014-11-20 Fabian Heitsch , Javier Ballesteros-Paredes , Lee Hartmann

We investigate the evolution of molecular clouds through the kinematics of their atomic hydrogen (HI) envelopes, using $^{12}\mathrm{CO}$ and 21-cm emission to trace the molecular and atomic gas, respectively. We measure the large-scale…

Astrophysics of Galaxies · Physics 2026-02-03 Thummim Mekuria , Nia Imara

The star-forming ability of a molecular cloud depends on the fraction of gas it can cycle into the dense-phase. Consequently, one of the crucial questions in reconciling star-formation in clouds is to understand the factors that control…

Astrophysics of Galaxies · Physics 2017-12-20 S. Anathpindika , A. Burkert , R. Kuiper

We find that clouds of optically-thin, pressure-confined gas are prone to fragmentation as they cool below $\sim10^6$ K. This fragmentation follows the lengthscale $\sim{c}_{\text{s}}\,t_{\text{cool}}$, ultimately reaching very small scales…

Astrophysics of Galaxies · Physics 2018-05-10 Michael McCourt , S. Peng Oh , Ryan M. O'Leary , Ann-Marie Madigan

We investigated two-dimensional brittle fragmentation with a flat impact experimentally, focusing on the low impact energy region near the fragmentation-critical point. We found that the universality class of fragmentation transition…

Statistical Mechanics · Physics 2007-05-23 Hiroaki Katsuragi , Daisuke Sugino , Haruo Honjo